Grief collar



H.H.CLARK GRIEF COLLAR Oct. 14, 1941.

Filed Aug. 4, 1939 E HBM,

Y. K ww f4., fw, ma

Patented Oct. 1.4, 194i GRIEF COLLAR.

Harry H. Clark, Los-Angeles, Calif.'l assigner to The National Supply Company. Pittsburgh, Pa.,l a corporation 4of Pennsylvania Application August 4, 1 939, Serial No. 288,312 14 Claims. (Cl. 30S-'4) This invention relates to grief collars,.and

'more particularly to a method of forming and construction of grief -collars particularly' applicable for use in drilling apparatus of the type emploryed in the rotary system of drilling wells l a grief collar which will not restrict materially and to an improved form of grief collar for use in conjunction with the drill string or pipe to protect the same against wear. -In the rotary process of drilling wells there customarily used a drill string formed of aplurality of sections `of pipe secured together by means of couplings.V In many cases the couplings utilized for securing together the sections of-pipey are of larger diameter than the pipe. As the drill string is rotated in the rotary process of drilling wells, the Pipe and such couplings receive Wear 'due to the rubbing thereof against the side of the hole or against the side of the casing used in the hole. Unless some adequate means of protection is provided, the pipe and the couplings are subjected to very rapid wear particularly enhanced by deviations of the well hole from a straight hole. As all well holes -of any appreciable depth deviate considerably i'rom a straight line, the vwear upon these pipes and couplings becomes very much more rapid at the points of deviation of the hole from the straight. There has heretofore been utilized in the rotary process of drilling wells rubber collars whichare interposed between the drill stern and the casing to protect the drill pipe and couplings from wear against the casing. It has been found, however,y

that these rubber collars are not satisfactory for use below the casing and in direct contact with the formation-being drilled.- When the rubber drill collars are utilized in the open hole or in direct contact with the formation, they are of very short life due to the fact that the rubber does not stand-the action against the formation. It is therefore an object of this invention to provide a 'protecting'collar commonly known in the art as a grief collar applicable for use in connection with a drill stem, which is particularly applicable for open hole use and which will eiectivelyoperate in direct contact with the well formation.

Another object of this invention is to provide the normal ilexure of the drill string.

Other objects and advantages of this invention it is believed. will be apparent from. the following detailed description of a preferred embodiment thereof as illustrated in the accompanying drawing.-

' In the drawing:

Figure 1 is a perspective view collar -embodying my invention.

Figure 2 is a transverse section of the grief collar as illustrated in Figure 1.

Figure 3 is a sectional elevation taken substantially on the line 3--3 of Figure 2.

' In each of Figures l, 2 and 3 the grief collars showing a grief embodying my invention are illustrated as adapted to a section of pipe.

Figure 4 is a transverse section of a modiiled form of grief collar embodying my invention likewise illustrating the same as adapted to a section of pipe.

In the drawing I0 indicates a section o! Vwell pipe or drill string" of any desired or preferred type as utilized inthe rotary process of drilling.

Asis well known in the art, sections or length of drill pipe I0 are joined together by suitable couplings (not shown) to form the drill string. As the term well pipe will hereinafter be utilized, it refers to the drill pipe or couplings or tool joints or any other of the well known elements utilized tomake up the drill string as the terial but is preferably formed of. steel to provide a hardened wearing surface I4. Thus the wear a grief collar having a wear member which is member II may be formed of high manganese steel which is very hard and has the peculiar characteristic of becoming harder as it is worked.

The wear member II is formed to provide a cavity I5 around the well pipe I0. This cavity is filled with a' sleeve of rubber I6. The rubber sleeve I6 is retained in the cavity under compression as,.for example, will be apparent from the fouowmg illustrative exanp of the method of application and compression of the sleeve I6 between the'wear member II and the well pipe IIl. In 4one illustrative example utilizing a well pipe of a 41/2 inches outside diameter the inside outer surface of the pipe. By the use of suitable clamps the two segments are compressed ltogether to apply an initial compression in the' sleeve I6 which substantially mounts to compressing the thickness of the rubber sleeve down to ta" or ther'eabouts, thus imparting a very material compression to the rubber. The two segments I2 and I3, while held clamped to the pipe and to the sleeve, are then welded together at the longitudinal seams I1 and Il whereby the sleeve I6 is maintained in compression. Thus a compressed sleeve of rubber is maintained between the wear element II and the well pipe I0. As this sleeve is tightly compressed against the pipe, it follows all possible irregularities of the pipe contour and firmly fixes the wear sleeve II in position upon the pipe against longitudinal movement along the length of the pipe.

In the form of grief collar illustrated in Figures 1, 2 and 3 the segments I2 and I3 at their adjacent longitudinal edges I9 are provided with inwardly projected ribs which cooperate with walls to act as a means for confining the rubber sleeve I6 against extrusion during the procto provide a lap-Joint by providing ribs 20a which ess of compressing the same. A welding cavity 2| isthus formed between the segments I2 and I3 which is free of' rubber. 'I'he welding cavities 2l are also provided with tapered walls 22 which facilitatethe process of forming. the longitudinal welds I'I 'and' I8. It is ,preferable during the formation of the longitudinal welds I'I and I8 to place yin the'bottom of the cavity some form of material such as asbestos or the like to prevent excessive heating oi' the well pipe` Ill. Thus the welds I'I and I8 may be formed to maintain the segments 'I2 and I3 together without danger of causing the same toadhere to, or to be welded to, the well pip'e, thus weakening the pipe at such welded points.

If desired, one or more recesses 23 may be formed from'the surface Il in the wear member Il. which recesses 23 are of known depth when the grief collar is installed in position. These recesses 23 then form a means of determining the amount of wear of the grief collar by checking the depth thereof from the surface Il so that the amount of wear along the'suri'ace I4 may be determined to enable the driller to know when such grief collar should be replaced orhas become dangerously thin due to wear.

In the modified form of my invention illustrated in Figure 4, similar parts have been designated with similar numerals with the addition tioning the two segments I2a andA I3a of the wear member IIa over the continuous ring. The two segments I2a and Ila arethen compressed against the sleeve l8r by the use of ilt within recesses 24a formed in the adjacent edge I3a of the opposite segment. .Thus the ribs 23a. in addition to forming means for vpreventing the extrusion of the rubber sleeve lia, also provide a means for closing the bottom of the weiding recesses 2Ia.

In both forms of the grief collar embodying my invention the metallic wear member as resiliently carried on the pipe acts as a resilient buffer. As no welds are required to maintain the wear member on the pipe and no welds are made into the well pipe, the same' is not weakened. As the wear member is not directly mounted on the pipe but there is interposed between it and the well pipe the resilient rubber sleeve, there is no high stress concentration in the pipe adjacent the grief collar but normal flexing is permitted.

It will be obvious that thespeciflc illustration hereinabove given is given merely for the purpose of enabling one skilled in the art to determine the exact method of carrying out my invention and is not intended to in any way limit my invention to any of the sizes, proportions or degrees as therein specified.

The grief collar embodying my invention furthermore may be mounted on any section of the well pipe intermediate the couplings or tool joints or may be4 mounted adjacent or directly upon the coupling or tool Joint if desired. Furthermore,

- the grief collar may be mounted on the pipe midway between couplings or'tool Joints in order to prevent wear on the pipe and decrease the amplitude of oscillation of the pipe as it is rotated l rubber-like material confined under compression between the wear member-and the pipe.

2. A grief collar for a rotating wellpipe, comprising a steel sleeve surrounding the pipe and supported-thereon by means of alayer of rubber confinedunder compression between the steel sleeve and the pipe.

3. In a grief collar for a well pipe, 'the combination of a metallic sleeve surrounding the pipe and comprising a plurality of segments, a layer of rubber-like material within each segment, means to confine the rubber-like material longitudinally and laterally within its respective segment, the,

segments being welded together to maintain the rubber-like material under compression between the sleeve and the pipe.

4. VAs an article of manufacture, a grief 'collar for a -well pipe. comprising a cylindrical steel sleeve surrounding the pipe, and formed as a pair of cooperating halves, a rubber'insert associated with each of said halves, means to confine each v rubber insert longitudinally within said sleeve, the

halves being integrally joined by welding to maintain the rubber under compression between the sleeve and the pipe.

5. In a grief collar for a well pipe, the combination of an outer metallic wear member surrounding the pipe comprising two substantially semicylindrical segments, an inner layer of resilient material interposed between the segments and the pipe, means to confine the resilient material longitudinally within said segments, and fastening means adapted to secure said segments together whereby the resilient material is maintained under compression.

6. In a grief collar'for a well pipe, the combination of a cylindrical steel wear member surrounding the pipe and formed as a pairof cooperating halves, inwardly directed ribs adjacent the lateral faces of each 'of said halves, a resilient liner disposed within each of said cooperating halves between said`ribs,vfastening means comprising ay weld integrally joining said cooperating halves together along said ribs, said fastening means lacting to maintain said resilient liners in compression between the cooperating halves and the pipey 7. In a grief collar for a well pipe, the combination of a cylindrical metallic wear member surpipe, and a resilient non-metallic member interposed between the wear member and the well pipe,

the resilient non-metallic member being the sole means for supporting the outer metallic wear member on the well pipe.

9. The method of lforming a grief collar 'for a well pipe, comprising placing a pair of cooperating segments of a metallic sleeve on opposite sides ofthe pipe, positioning one or more rubber inserts'between the segments and the pipe, clamp,-

ingtl'e cooperating segments together to com' press the rubber inserts, and fastening the segments while they remain clamped together in order to maintain the rubber inserts under initial compression. l

10. vThe method of making a grief collar for a well pipe, comprising placing a pair of cooperating segments of a metallic sleeve on opposite sides of the pipe, positioning a` layer of resilient material in pockets formedv in the segments, clamping the cooperating segments together to compress the resilient material between the segments and the pipe, and fastening the segments While they remain clamped together inorder to maintain the resilient material under initial compression.

11. The method of forming a grief collar for a well pipe, comprising'positioning a layer of rubber-like material around the pipe, clamping a pair of cooperating metallic segments on opposed sides of the pipe to compress the rubber-like material between the metallic segments and the pipe, and welding the adjacent lateral faces of the segments together while they remain clamped together in order to form an integral wear member surrounding the pipe.

12. The method of making a grief collar for a well pipe, comprising placing a pair of cooperating segments of a metallic sleeve on opposite sides of the pipe, positioning a layer of resilient material between the segments and the'pipe, bringing the cooperating segments together initially until their adjacent lateral faces meet to limit the compression ofthe resilient material, and securing the segments together against separation in order to maintainl the resilient material under initial compression.

`13. A grief collar for a well pipe, having in combination a pair of cooperating segments adapted to encircle the pipe, inwardly directed ribs formedon each Isegment along its lateral edges, inwardly directed walls lformed o n each segment along its upper and lower ends, the said ribs and walls cooperating to denne a cavity within each of said segments, a resilient liner disposed within each of said cavities, the segments beingl v welded together along their adjacent ribs whereby the resilient liners are maintained under initial compression between the segments and the pipe, and are confined against extrusion by said ribs and Walls.

14. In a grief collar for a well pipe, the combination'of ametallic sleeve surrounding the pipe HARRY H. CLARK. 

